Azole rings are present as (among other properties) insect defense properties in many plants, with cereals kind-of specialized in hydroxamic azaleas (Dimboa and family), and some legumes as isoxazole accumulators (isoxazolinones mostly).

See some refs on these two pathways, but there are plenty of. Maybe you could find diazos in such families, or restricted genuses  within poacea and papilionoidae ?

Hope this helps

Yvan

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